Mora's blog

Writing on this blog

Wed, 21 Oct 2026 00:00:00 +0000

Everything is plain Markdown. Write, git push, and the site rebuilds itself on GitHub Pages.

New post #

hugo new posts/my-post/index.md # a folder per post, so images live next to it
hugo server # preview at http://localhost:1313
git add . && git commit -m "New post" && git push

A cheatsheet goes in content/cheatsheets/ instead. Creating the folder by hand (from Obsidian or nvim) works the same as hugo new.

Front matter #

---
title: "My post"
date: 2026-10-21 # recommended: without it, the last commit that changed the file is used
tags: [prometheus, slo]  # optional
description: "One line for link previews." # optional
draft: true # optional: hides it from the published site
toc: false # optional: hides "On this page"
---

Don’t repeat the title as a # Heading in the body: the page prints it already. Sections start at ##.

Grafana Dashboards: A Complete Guide

Sat, 03 Jan 2026 00:00:00 +0000

Introduction #

Dashboards are easy to create but difficult to maintain at scale. Without a clear strategy, organizations often face “dashboard sprawl.” The following classification scheme helps organize dashboards based on business processes and engineering needs.

1. Methodologies: USE & REDS #

Foundational dashboards for SREs. These should be visually simple, uniform, and composed primarily of time-series panels.

LogQL Cheat Sheet

Sat, 03 Jan 2026 00:00:00 +0000

Loki Query Language reference for log aggregation and analysis.

Query Types #

Type	Returns	Example
Log queries	Log lines	`{job="nginx"}`
Metric queries	Numeric values	`rate({job="nginx"}[5m])`

Log Stream Selectors #

Basic Selection #

# Single label
{job="nginx"}

# Multiple labels (AND)
{job="nginx", env="production"}

# Multiple values (OR - use regex)
{job=~"nginx|apache"}

Label Matching Operators #

Equality

# Exact match
{job="nginx"}

# Multiple exact matches
{job="nginx", namespace="default"}

Inequality

# Not equal
{job!="nginx"}

# Exclude namespace
{namespace!="kube-system"}

Regex

# Match pattern
{job=~"nginx.*"}

# Match multiple
{job=~"nginx|apache"}

# Negative regex
{job!~"test.*"}

Log Pipeline #

Chain operations to filter and parse logs:

PromQL Cheat Sheet

Sat, 03 Jan 2026 00:00:00 +0000

Prometheus Query Language reference for monitoring and alerting.

Metric Types #

Type	Description	Use Case
Counter	Monotonically increasing value	Request counts, errors
Gauge	Value that can go up or down	CPU usage, memory, temperature
Histogram	Distribution of observations	Request latency, response sizes
Summary	Similar to histogram with quantiles	Precomputed percentiles

Data Types #

Instant Vector - Set of time series at a single timestamp

SLIs, SLOs, and SLAs

Sat, 03 Jan 2026 00:00:00 +0000

1. Planning #

Service Level Objectives (SLOs) distinguish themselves from standard alerting and monitoring by focusing strictly on operations that matter to the user.

The Planning Workflow #

Step	Description	Example
1. Operation	A customer-facing operation important enough to warrant an SLO.	A new order is generated, submitted, and acknowledged.
2. SLI (Indicator)	The measurable data needed from the system to compute the SLOs.	Latency in seconds from “order submitted” to “order acknowledged” (derived from logs/telemetry).
3. Aggregation Window	A timeframe meaningful to the business to spot trends/hotspots.	8 hours.
4. Target Reliability	The percentage of success required. (Prod usually > 99%).	90% (for this example).
5. SLO (Objective)	The combination of the Indicator and the Target.	New orders are acknowledged within 1 second and achieve this level of service 90% of the time.

Categories of SLIs #

Based on “Database Reliability Engineering” by Laine Campbell & Charity Majors.